The Topeak iGlow Cage with Bottle is an ideal gift or addition to your bike if you are finding yourself commuting to and from work in the darker hours of the day. This shouldn\\\'t be used as your main light, (obviously) but working alongside a good set of lights This acts as a great side light. If you use alongside a front and rear light you have exceptional 360 degree lighting coverage. The Bright RGB LED gives you the choice of 5 colours, matching with any bikes aesthetics with ease. The bottle cage is the part that holds the LED and once you place your bottle in the cage the bottle illuminates and glows. Overall this is a great product to own and also adds a futuristic feel to it.